#include<bits/stdc++.h>

using namespace std;

//prime or composite
int main() {
    int n = 1e9 + 7;//1000000007
    int flag = 0;
    if (n % 2 == 0) {
        if (n == 2) {
            cout << "yes";
        } else {
            cout << "no";
        }
        return 0;
    }
    for (int i = 3; i <= n / i; i += 2) {
        if (n % i == 0) {
            flag = 1;
            break;
        }
    }
    if (flag == 0) {
        cout << "yes";
    } else {
        cout << "no";
    }
    return 0;
}
